S-2.1, r. 13 - Regulation respecting occupational health and safety
253. Signalman: If the operator of a hoisting device does not have an unrestricted view during any manoeuvre, one or more signalmen shall assist the operator. The signalman shall:
(1) observe the movement of the apparatus or the load when it is out of sight of the operator;
(2) communicate with the operator by a well-established, uniform signal code or by means of a telecommunication system, when conditions so require or when the operator judges it necessary.